Compound for use in soldering aluminum and process of forming same.



'rnr ;FFICE.

. JOHN J. NATZMAN, OF DETROIT, MICHIGAN.

COMPOUND FOR USE IN SOLDERING ALUMINUM AND PROCESS OF FORMING SAME.

N0 Drawing.

12) all whom it may cancer/1.:

Be it known that I, JOHN J. NATZMAN, a citizen of the United StatesofAmerica, residing at Detroit, inthe county of Wayne and State ofMichigan, have invented certain new and useful Improvements in Compoundsfor Use in Soldering Aluminum and Processes of Forming Same, of whichthe following is a specification, reference being had therein to theaccompanying drawings.

The invention relates to compounds for use in soldering aluminum, andconsists in the composition and method of forming same ashereinafter setforth.

In the formation of my compound I mix nitric, sulfuric and hydrochloricacids preferably in equal proportions, and add to the mixture a smallquantity of rosin; I then add an excess of aluminum by inserting a smallfragment of' metallic aluminum and permitting it to remain untilreaction ceases. In a separate vessel I then place nitric acid and adda'small quantity of rosin, and in a third vessel mix nitric andhydrochloric acids in equal proportions, adding rosin to this mixturealso. I then combine the three mixtures in equal proportions, theresulting combination being then ready for use.

The surfaces to be soldered are first cleaned with this compound, whichmay either be applied with a swab or the metal may be dipped in thesolution. After cleaning, the adhering liquid is wiped off to dry thesurface and a small quantity of powdered rosin is sprinkled on. Thecleaned surfaces are then coated, preferably with metallic zinc whichmay be applied with an ordinary soldering iron. I have found that wherethe surfaces are treated in the manner above described the zinc willreadily adhere to the surfaces, after which the soldering may becompleted by the use of any ordinary solder. p

While I do,notfully understand the nature of the chemical reaction thattakes place in carrying out my process, practical tests have provenconclusively that aluminum surfaces so treated can be easily soldered.

What I claim as my invention is:

l. A compound for use in soldering aluminum, comprising a mixture ofnitric, sulfuric and hydrochloric acids with a small quantity of rosinand a small quantity of aluminum dissolved in said acids.

2. A compoundfor use in soldering aluminum comprising a mixture ofnitric, sulfuric and hydrochloric acids, with a small quantity of rosinand a small quantity of aluminum dissolved in said acids, and anadditional quantity of free nitric and hydrochloric acids.

3. A- process for forming a compound for use in soldering aluminum whichconsists in mixing nitric, sulfuric and hydrochloric acids, adding asmall quantity of rosin thereto and metallic aluminum in excess and thenadding an additional quantity of free nitric and; hydrochloric acids.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN J. NATZMAN. Witnesses: FRANK NATZMAN, THOMAS A. GARYEFSKL.

Specification of Letters Patent. Patented July 16, 1912. Applicationfiled April 26, 1912. Serial No. 693,420,

